This invention relates to a paper feeding controlling method for a printer.
A conventional paper feeding controlling method for a printer will first be described with reference to FIGS. 2(a), 2(b) and 2(c) of the accompanying drawings in which successive different stages of a paper feeding operation of a printer are illustrated in schematic representation.
The printer shown includes a print head 1 such as a wire dot print head or a thermal head, a platen 2, a first pressure roller 3 mounted for movement into and out of contact with the platen 2, a second pressure roller 4 having a smaller diameter than the first pressure roller 3 and mounted for movement into and out of contact with the platen 2 similarly to the first pressure roller 3, and a paper bail roller 5 for pressing record paper 6 against the platen 2.
Conventionally, in such a paper feeding mechanism as described above, record paper 6 is first fed by the platen 2 and the first and second pressure rollers 3 and 4 to a position a little farther than a recording position between the print head 1 and the platen 2 as shown in FIG. 2(a). Subsequently, while the record paper 6 is being fed further, the paper bail roller 5 is moved out of contact with the platen 2 so that a leading end of the record paper 6 passes between the platen 2 and the paper bail roller 5 as shown in FIG. 2(b) whereupon the feeding of the record paper 6 is stopped. Then, the paper bail roller 5 is moved toward the platen 2 to press the record paper 6 against the platen 2 as shown in FIG. 2(c). Thereafter, printing will be initiated.
It is to be noted that the position of the leading end of the record paper 6 in the paper feeding operation described above can be readily determined by controlling the amount of rotation of the platen 2 with reference to a distance from a position at which the first pressure roller 3 and the platen 2 contact with each other to another position of either the print head 1 or the paper bail roller 5.
However, such a paper feeding controlling method as described above has a drawback that, since printing is initiated after such a condition as shown in FIG. 2(c) has been reached, a portion of the record paper 6 from the print head 1 to the paper bail roller 5 cannot be printed and hence will remain blank.